Compare that to the thousands of dollars an average medical plan in the US costs - and we still have to pay out of pocket for many medical expenses too!
The 400$ only covers the use of a bike. There's also 0.95% of you salary taxed for workplace injuries and 1.26% for non-work injuries. Then there's car registration which is about 200$/yr and a tax added to petrol which comes included in the $/Litre cost (they put the figure at 330$/yr). 2600$ is a rough estimate of my ACC levies paid each year. I think there's also some portion of cigarettes and booze that goes to ACC as well.
One of the negatives is that when you're in need of an operation but it's not immediately life threatening you're prioritised and end up on a wait list which could be several years long.
A bit off topic, but there are definitely good and bad aspects to both systems.
I'd much rather pay $400 a year.